Armide is an opera by Jean-Baptiste Lully. The libretto was written by Philippe Quinault, based on Torquato Tasso's La Gerusalemme liberata (Jerusalem Delivered).

Critics in the 18th century regarded Armide as Lully's masterpiece. Unlike most of his operas, Armide concentrates on the sustained psychological development of a character — not Renaud, who spends most of the opera under Armide's spell, but Armide, who repeatedly tries without success to choose vengeance over love.

The work is in the form of a tragédie en musique, a genre invented by Lully and Quinault.

Lully's Armide was first performed on 15 February 1686 by the Paris Opera at the Théâtre du Palais-Royal, with scenery by Bérain, in the presence of the Grand Dauphin. To Lully's great distress, however, the king would not attend the première or any of the following performances. The opera was revived by the Paris Opera in 1703, 1713–14, 1724, 1746–47, 1761, and 1764.